Hello, if I can give you fiew precisions concerning this case.
The problem appeared after holding the power button for couple of seconds (maybe 7sec) insead of just taping it and turning the monitor off just after with the main power button on the back.
Actually i still have the 3 leds blinking.
In order what is happening :
-Put main power on. Standby led blinking 2 times, and overdrives lights up, the power and it starts blinking (all 3 leds at the same time).
-If I press Power button, it stops blinking and power is light up, but after couple of seconds i head degauss sound, and a clic from the alimentation bloc at the same time the overload lights up for 1 sec, then it return to 3 leds blinking.
-If I press Power button again, it lights standby and nothing happends, then it returns to 3 leds blinking.
-If I press again power its power light.. etc etc... its a cycle.
-If i press power and when its the power lighs up, if i activate brightness and contrast button, they light up, and if I try to turn the roll in the opposite way of watch loop, the button power is still activate the time i'm keep rolling them. When I stop rolling, it clics and return to 3 leds blinking.
I also noticed that when the monitor is trying to power on, whe the green power led is active and stops, they are a red led on the alimentation board, activate just the time of the "clic" before 3 leds blinking again. Its the red led right in the middle of the alimentation card.
I have two leds activated all the time on the alimentation board. (the red led on the left of the board and the green led, not the one on the most right but the other one.
I have controlled CN501 pins 1 and 5 with a multimeter, when i start the monitor there is absolutely nothing on it (between 0.30 and 0.45V) and it rises to 7~8V when it turns off (just before 3 blinking led coming).
to me the problem is from the Alimentation card or the E board. but i do not know.
The monitor was also working aboslutely fine before this "power button holding... i don't understand how i could have break something with just pushing a button. To me it looks locked by a kind of security or something.
If those info can help you to help me to know what to do to fix the problem.